The background description provided herein is for the purpose of generally presenting the context of the present invention. The subject matter discussed in the background of the invention section should not be assumed to be prior art merely as a result of its mention in the background of the invention section. Similarly, a problem mentioned in the background of the invention section or associated with the subject matter of the background of the invention section should not be assumed to have been previously recognized in the prior art. The subject matter in the background of the invention section merely represents different approaches, which in and of themselves may also be inventions. Work of the presently named inventors, to the extent it is described in the background of the invention section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present invention.
To provide a mobile operating platform for maintenance of a bridge underside with heavy traffic, a patent application was filed to the State Intellectual Property Office on Apr. 17, 2012, with No. 2012101125274 and title “BRIDGE MAINTENANCE VEHICLE WITH HINGE-CONNECTED TYPE HANGING BRACKET”, referring to FIG. 1 to FIG. 6. The maintenance vehicle includes a vehicle frame and a suspension arm capable of extending outside of a bridge. The vehicle frame includes a vehicle frame chassis. The suspension arm is a C-shaped hanging bracket. The vehicle frame chassis hinges a lower end of a strut through a longitudinal shaft hinge together with a longitudinal shaft. An upper end of the strut hinges a extending end of an upper cross beam of the C-shaped hanging bracket through a horizontal shaft hinge and a horizontal shaft; or the vehicle frame chassis hinges the extending end of the upper cross beam of the C-shaped hanging bracket through a universal joint or a spherical hinge; or the vehicle frame chassis hinges the extending end of the upper cross beam of the C-shaped hanging bracket through the longitudinal shaft hinge and the longitudinal shaft, and an extending end of a lower cross beam of the C-shaped hanging bracket is provided with at least a fixing point for a lifting rope or a lifting rope winding/unwinding device. The strut and the C-shaped hanging bracket form an inverted G-shaped rigid frame in a plane, which can avoid bridge-side railings and directly transfer pulling force of the lifting rope of a maintenance platform to a deck, with a small overturning moment and a compact structure, easy to assemble and use, capable of being erected on sidewalks on two sides of the bridge, not occupying lanes, not affecting vehicle traffic on the deck in use, and especially applicable to projects of inspection and maintenance on an underside of a bridge with heavy traffic. However, the maintenance vehicle may often be obstructed by cables or lampposts on two sides of the bridge during construction. In this case, it is necessary to consider arranging two sets of vehicle frames on two sides of the deck respectively, that is, two vehicle frames are arranged on each side of the bridge respectively, so as to avoid cables, lampposts or other obstacles on two sides of the bridge by alternating forces of the lifting ropes on C-shaped hanging brackets of the two vehicle frames and by replacing lifting points of the lifting ropes to make the lifting ropes swing and transit between the two C-shaped hanging brackets, thereby realizing movement of the operating platform at the bottom of the bridge. During the above process of avoiding obstacles, it is necessary to assemble two additional maintenance vehicles respectively on the two sides of the deck and to frequently change the lifting points of the lifting ropes of the underbridge operating platform to transit and avoid the obstacles, which costs lots of labors and time, has high construction costs, and is inefficient and cumbersome. Lifting equipment is also needed during on-site assembling of the maintenance vehicles, which would temporarily occupy the lane and affect the traffic.